My daughter is grinding her teeth!

My oldest is 13/14 months old. She’s been teething and got four of her top teeth all at the same time. I’m pretty sure she has more that are about to cut, because her eating habits changed. A routine that we’re used to by now. She’s laying on me watching her super simple songs and I can hear her grinding her teeth. I tell her no and to stop, but she’s one. Is she doing this because of the teething and it hurts? Do I give her Tylenol? How do I get her to stop?